In Situ Observation of Nonequilibrium Local Heating as an Origin of Special Effect of Microwave on Chemistry

Abstract

We successfully observed the phenomenon of “nonequilibrium local heating” occurring to the DMSO molecules in proximity of the Co particles under microwave irradiation by real-time in situ Raman spectroscopy. This phenomenon was induced only under microwave irradiation but not by conventional heating. This nonequilibrium local heating can be realized by the input of the power more rapid than that of the heat loss induced by the temperature difference between the heated microdomains and the surrounding domains. We have demonstrated the enhancement in the dehalogenation reaction of the C(sp3)−Cl bond of 2-chloroethylbenzene and 4-phenylbutyl chloride caused by the “nonequilibrium local heating” of the surface of the Co and/or Fe particles under microwave irradiation.